<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>CSS选择器-儿子选择器</title>
    <style>
        .one{
            margin: 0px auto;
            width: 500px;
            height: 500px;
            border: 1px dashed red;
        }
        /*后代选择器*/
        /*只要是.one下的所有div都有效*/
        .one div{
            width: 200px;
            height: 200px;
            margin: 2px;
            border: 1px solid black;
        }
        /*儿子选择器*/
        .one > div{
            border-color: green;
        }
    </style>
</head>
<body>
<div class="one">
    <div class="two">
        <div class="three">
            <div class="four">

            </div>
        </div>
    </div>
    <div></div>
</div>
</body>
</html>